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Drugs & Health Blog

Tolerance, Dependence, Addiction: What's the Difference?

This blog post is archived and is no longer being updated. For the latest content, please visit the main Drugs & Health Blog page.
The NIDA Blog Team

Many people think drug addiction, dependence, and tolerance are pretty much the same thing. But in fact, each term means something very different about how drugs affect a person’s body and brain. Learning the difference is important.


Tolerance happens when a person no longer responds to a drug in the way they did at first. So it takes a higher dose of the drug to achieve the same effect as when the person first used it. This is why people with substance use disorders use more and more of a drug to get the “high” they seek.


Dependence means that when a person stops using a drug, their body goes through “withdrawal”: a group of physical and mental symptoms that can range from mild (if the drug is caffeine) to life-threatening (such as alcohol or opioids, including heroin and prescription pain relievers). Many people who take a prescription medicine every day over a long period of time can become dependent; when they go off the drug, they need to do it gradually, to avoid withdrawal discomfort. But people who are dependent on a drug or medicine aren’t necessarily addicted.


Unlike tolerance and dependence, addiction is a disease; but like tolerance and dependence, addiction can result from taking drugs or alcohol repeatedly. If a person keeps using a drug and can’t stop, despite negative consequences from using the drug, they have an addiction (also called a severe substance use disorder). But again, a person can be dependent on a drug, or have a high tolerance to it, without being addicted to it.

Learn more: Marijuana withdrawal is real.

Comments posted to the Drugs & Health Blog are from the general public and may contain inaccurate information. They do not represent the views of NIDA or any other federal government entity.


How can this ever-growing need be stopped?

One way is by educating people on the dangers of using drugs, so hopefully they never start in the first place.

Doctors have a responsibility to warn patients of the possibility of dependence when they offer prescription drugs. This does not always happen.
I feel people shouldn't be experiments for science research especially if they aren't recieveing compensation for it and there are other ways to heal besides prescription drugs.
that is so true well done for thinking about other people in the world some drugs go from legal to illegal drugs
Which of the these three are the worst?

Addiction is the worst, because the person continues to use despite negative consequences. Even if they lose their job, fail in school, or get in trouble with the law, they keep using. They hurt not just themselves but many others around them.


There are no illicit drugs that have been proven to help you safely lose weight. People with severe substance use disorders often substitute food for drugs, and will lose nutrition and weight, with very unhealthy outcomes.

It sounds like addiction is the big issue. (I think you can become tolerant or dependent to stuff that no one would abuse like pills for allergies or depression.) So is it possible to use drugs responsibly and not become addicted? Alcohol is addictive, but most adults use it responsibly and don't become alcoholics. So is it possible for adults to use pot responsibly? Do most adults using pot become addicted? Do people stopping get those life threatening withdrawal symptoms? It seems like pot is worse than alcohol mostly because it's illegal. If alcohol is addictive do you drink or hang out with people who drink responsibly?

Unfortunately, there’s no way for us to know who will become addicted and who won’t. There are many factors that influence a person's risk of addiction. For example, different drugs have different effects on the brain and body, and the risks can also vary based on individual factors such as a person’s physical health, genetics, and social support. But all drugs have a risk for addiction.
Learn more about what puts you at risk: view our video, Anyone Can Become Addicted to Drugs at

It also depends on their parents most of the time if the parent does drugs they'll do drugs because they were never raised to learn to not do them drugs because their parents were on them.
dont get it
Really cool stuff guys
be safe never do drugs
Habituation: It is a condition resulting from the repeated consumption of a drug characterized by desire to take it. Desire (but not a compulsion) to continue taking the drug for the sense of improved well-being which it engenders. There is Little or no tendency to increase the dose, some degree of psychic dependence on the effect of the drug but absence of physical dependence. e.g. Desire to sex with partner is a habituation. Tolerance: Tolerance is defined as a person’s diminished response to a drug that is resulted from repeated use.There is tendency to increase the dose, absence of compulsion with little or no dependency. e.g. patients with chronic pain frequently develop tolerance to pain relieving medications with (opioids) or without developing an addiction to them. Dependency: A state in which a person functions normally only in the presence of a drug. There is tendency to increase the dose, both physical and psychic dependence present here. If you with drug dependence & stops taking that drug suddenly, you will experience predictable and measurable symptoms, collectively known as a withdrawal syndrome. Chronic dependency leads to addiction. Addiction: Addiction is a state of chronic or periodic intoxication produced by the repeated consumption of a drug (natural or synthetic) despite harmful consequences. It is characterized by an overpowering desire or need (compulsion) to continue taking the drug and to obtain it by any means, tendency to increase the dose, psychic (psychological) and physical dependence on the effects of the drug with detrimental effect on the individual and on society. You may experience addiction from tobacco, marijuana, opioids, alcohol, sedatives (benzodiazepines) etc. --one alone or one along with other. Thanks
Which of the three is the most common among teenagers? And which one are teens most susceptible to?

Interesting question, but data is not collected in this way. The three are interconnected. If you are addicted, you have developed a dependence. If you have developed a tolerance, it increases your chance of addiction, because you will want to take more and more of the drug to get the same effect. Teens who are taking medicines for a disease condition can become dependent without becoming addicted, especially if they are carefully monitored by a health care professional. This means they might experience uncomfortable withdrawal symptoms if they try to stop taking the medication suddenly, and should seek advice from their doctor on how to stop taking the drug safely and comfortably.

Excellent conceptions..... Thanks to make me clear about addiction, tolerance and dependency
Please try to stay safe. Recently marijuana addiction increased dramatically. Following article may be helpful for them.
seems like a very fine line--almost semantics--between dependence and addiction. If you do not function normally without the drug are you going to be able to stop? How does withdrawal differ between the two?

A major sign of addiction is that you seek more and more of the drug, and that your relationships and life begin to suffer. You might even start stealing to buy drugs. This does not generally happen with dependence. Dependence simply means you get withdrawal symptoms when you stop using a drug. Withdrawal symptoms can be similar, which is why you should ask a medical professional to advise you when you stop taking a drug---whether it is dependence or addiction.

Excellent! So it is safe to conclude that chronic smoking should be considered an addiction,while vaping, at worst, is a dependency.
you explain about tolerance, dependence and addiction so how about habituation ?

Habituation is a form of learning where a person has a diminished (lower) response to a stimulus as they’re exposed to it over and over. For example, when a person repeatedly takes cocaine, they become habituated to its effects, so over time, using the drug has less of an effect on them.

I have learned a lot about drugs and the dangers of taking them. Why would anyone take them in the first place if they know all these bad things could happen to them. Also, is drug addiction a disease and why?

These are great questions. While the specific answer may differ from person to person, some common reasons are for why people would start taking drugs is that people think they will feel good, forget their problems, perform better, or fit in. Learn more by reading our blog post, "Real Teens Ask: Why Take Drugs?":

Yes, addiction is a disease. When a person takes drugs or drinks alcohol over a period of time, it can change their brain circuits. To learn more, please read our blog, "Addiction Is a Disease":

There are people that are in constant, chronic pain that take some of these as prescriptions. Nothing else helps to relieve the pain. Yet, because of the news lately, they are being looked down on because they use these drugs. This is not right. No one know the pain they are experiencing and what works for them. At the same time, I would never want to see anyone use these if they don't need them and feel bad for anyone who becomes addicted. Thank you for the info on this page. I learned much here.
how are drug tolerance and dependence connected to the possibility of overdosing?

Great question, Khaled! When you hear the word “overdose,” you probably assume it means “dying from taking drugs.” But it doesn’t always result in death. “Overdose” can also mean that a person used enough of a drug to have an uncomfortable or life-threatening reaction, but they didn’t die. Any type of overdose is serious, though, and requires fast medical help. For more information on overdose, please read this blog post:


You can become habituated to something in your environment when you experience it often or continuously. For more information, check out this blog:

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